September weather forecastForest Mill, TN
September
Weather in September
September, the first month of the autumn in Forest Mill, is also a moderately hot month, with an average temperature varying between 61°F (16.1°C) and 80.6°F (27°C).Temperature
September's onset records an average high-temperature of a still warm 80.6°F (27°C), a near match to August's 85.6°F (29.8°C). Forest Mill temperatures generally rest at a low of 61°F (16.1°C) during the September nights.Heat index
September's mean heat index is computed to be 84.2°F (29°C). When exposure and activity are sustained, they could induce fatigue, with a chance of heat cramps.Data suggests that the heat index is set for environments in shade and with a light wind. Exposure to unobstructed sunshine could lead to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', blends air temperature and moisture content to represent the felt temperature to humans. The effect is personal, with varied weather perceptions among individuals due to differences in body mass, stature, and physical activity. Consider the sun's direct rays and their impact; they can potentially increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Youngsters are usually more at risk than adults, considering they sweat less. Additionally, their high skin surface area compared to their little bodies and their high heat production due to activity increases their risk.
Humidity
The average relative humidity in September is 76%.Rainfall
The month with the least rainfall is September, when the rain falls for 14.1 days and typically collects 2.28" (58mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 23min.On the first day of September, sunrise is at 6:16 am and sunset at 7:10 pm. On the last day of the month, sunrise is at 6:38 am and sunset at 6:28 pm CDT.
Sunshine
In September, the average sunshine is 8.3h.UV index
In Forest Mill, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum UV index of 5 during September leads to these instructions:
Take necessary precautions - Protection from skin and eye injury is mandatory. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Forest Mill, TN
- Average high temperature in September: 80.6°F
The warmest month (with the highest average high temperature) is July (86.4°F).
The month with the lowest average high temperature is January (45.1°F).
- Average low temperature in September: 61°F
The month with the highest average low temperature is July (67.3°F).
The coldest month (with the lowest average low temperature) is January (30.7°F).
Average pressure in September
Forest Mill, TN
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in September
Forest Mill, TN
- Average wind speed in September: 5mph
The windiest month (with the highest average wind speed) is February (8.1mph).
The calmest month (with the lowest average wind speed) is July (4.6mph).
Average humidity in September
Forest Mill, TN
- Average humidity in September: 76%
The months with the highest relative humidity are March and December (80%).
The months with the lowest relative humidity are October and November (75%).
Average rainfall in September
Forest Mill, TN
- Average rainfall in September: 2.28"
The wettest month (with the highest rainfall) is July (4.72").
The driest month (with the least rainfall) is September (2.28").
Average rainfall days in September
Forest Mill, TN
- Average rainfall days in September: 14.1 days
The month with the highest number of rainy days is July (21 days).
The month with the least rainy days is November (10.3 days).
Average snowfall in September
Forest Mill, TN
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.34").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Forest Mill, TN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (5.2 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Forest Mill, TN
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in September: 8h and 18min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 24min).
Average sunshine days in September
Forest Mill, TN
- Average sunshine days in September: 14.1 days
The month with the most sunshine days is October (17.8 days).
The month with the least sunshine days is July (8.1 days).
Average UV index in September
Forest Mill, TN
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover in September
Forest Mill, TN
- Average cloud cover in September: 33
The month with the most cloud cover is February (Cloud cover 55).
The month with the least cloud cover is June (Cloud cover 31).
Average visibility in September
Forest Mill, TN
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, June, September, October and November (6mi).
The months with the lowest visibility are January, May, July, August and December (5mi).





